Sun scorch destroying blueberry patch?

brandond(6)July 11, 2012

After 100 plus degree temps for 17 straight days Im losing blueberry bushes hand over fist. These are two year old bushes most were healthy lush green and 2 to 3 ft tall prior to these temps. I have leaf scorch surrounding the leaves and on some, and just ends up burning the whole leaf. I also have observed browning of stems and eventually just killing the whole stem. It starts out as a maroon stem going along the length of the stem, then it ends up brown and killing the stem. Has anyone else experienced this issue. I still have a portion of the bushes that are healthy and only have minor dieback problems. IM guessing the smaller the bushes the more prone to extreme heat is the problem. These bushes have been adequatly watered and the ph lowered to appropriate leavels as well. IM very discouraged and have already placed a fall replacement order for some new ones. thanks

Brandond, Yes I have a similar condition with my 2 yr. old blueberry plants. I've done considerable research on the internet and came to the conclusion its either bacterial or a fungal or both, I just don,t know. Very disapointing. I questioned the oval elongated dark spots on the stems last year, here on GW. The plants that I have the problems with, came from a very well known, reputable plant supplier and I just couldn't believe that they would have a promlem with their plants. I,m interested on the replies you will get. luke

IM not sure of anything other than im losing to many bushes. Some bushes get a tan/maroon color on the stems and the leaves start burning from the outside in. I would hope that it is something other than the heat, in fact I went ahead and sprayed with a fungicide since I wasnt sure. I would feel better about it if it was a fugus rather than heat since our summers have been running on the hotter side the last few years. I would also say that the bushes that were a bit iron cholorotic have done worse that the lush colored bushes. Still this has been a sudden dismantling of my overall numbers. I have fertilized as soon as 2 weeks ago with iron sulfate. Could fertilizer burn the bushes this way? I used iron sulfate and amonium sulfate.

Luke, the elongated maroon ovals are a type of canker disease. One of the first blueberry plants I bought was a Premire Rabbiteye from Home Depot. It had alot of the dark oval blotches on its steams but I didnt know better at the time. It died with in a year. I should have cut the plant back to the soil but didnt. Oh well, that was a lesson learned.

I apply one tablespoon of Schultz's Plant Food-acidic formula, dissolved in 4 gallons of cold tap water, to each of our blueberry shrubs. There are two applications, one in late March, and the second in April. The latest I have ever applied fertilizer is mid-May. That is all the feeding our blueberry shrubs get, however I do water, and apply agricultural sulfur as needed, to lower soil pH. I have also used Miracle-Gro on our blueberry shrubs, using the same method outlined above. Our shrubs are generally healthy, although I do see a little rust now & then, which is pruned away.

Southern rabbiteye blueberries are a different plant than highbush blueberries (corymbosum sp?)

The former are not going to be damaged by heat like the highbush. My highbush couldn't stand heat like that either. Mine suffered terribly when we would get dry heat 95 + degrees. They are from New England where 100 degree dry heat days never occur. I plant mine here in part sun. Full sun is for other plants who demand/prefer it.
John S
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